Amazon App Store - Location of the downloaded APK

Where does this app store save the downloaded APK file? I have a problem where certain apps will only install when the sdcard is unmounted. The Amazon App store needs sdcard to be mounted

Answer

This is based on my EVO, but they appear to download into the Appstore's "private" external storage directory, which is /sdcard/Android/data/com.amazon.venezia/cache/. From what I've seen they appear to then get deleted after being installed, but anything which has been downloaded and not installed looks to be there.